Mapping exception while executing Rollup job - elasticsearch

Question

I have a Kibana instance which stores log data from our java apps in per daily indexes, like logstash-java-beats-2019.09.01. As far as amount of indexes could be pretty big in future I want to create a rollup job, to be able to archive old logs in separate index, something like logstash-java-beats-rollup. Typical document in logstash-java-beats-2019.09.01 index looks like this:
{
"_index": "logstash-java-beats-2019.10.01",
"_type": "_doc",
"_id": "C9mfhG0Bf_Fr5GBl6kTg",
"_version": 1,
"_score": 1,
"_source": {
"#timestamp": "2019-10-01T00:02:13.756Z",
"ecs": {
"version": "1.0.0"
},
"event_timestamp": "2019-10-01 00:02:13,756",
"log": {
"offset": 5729359,
"file": {
"path": "/var/log/application-name/application.log"
}
},
"tags": [
"service-name",
"location",
"beats_input_codec_plain_applied"
],
"loglevel": "WARN",
"java_class": "java.class.name",
"message": "Log message here",
"host": {
"name": "host-name-beat"
},
"#version": "1",
"agent": {
"hostname": "host-name",
"id": "a34af368-3359-495a-9775-63502693d148",
"ephemeral_id": "cc4afd3c-ad97-47a4-bd21-72255d450232",
"type": "filebeat",
"version": "7.2.0",
"name": "host-name-beat"
},
"input": {
"type": "log"
}
}
}
So I created a rollup job with such config:
{
"config": {
"id": "Test 2 job",
"index_pattern": "logstash-java-beats-2*",
"rollup_index": "logstash-java-beats-rollup",
"cron": "0 0 * * * ?",
"groups": {
"date_histogram": {
"fixed_interval": "1000ms",
"field": "#timestamp",
"delay": "1d",
"time_zone": "UTC"
}
},
"metrics": [],
"timeout": "20s",
"page_size": 1000
},
"status": {
"job_state": "stopped",
"current_position": {
"#timestamp.date_histogram": 1567933199000
},
"upgraded_doc_id": true
},
"stats": {
"pages_processed": 1840,
"documents_processed": 5322525,
"rollups_indexed": 1838383,
"trigger_count": 1,
"index_time_in_ms": 1555018,
"index_total": 1839,
"index_failures": 0,
"search_time_in_ms": 59059,
"search_total": 1840,
"search_failures": 0
}
}
but it fails to rollup the data with such exception:
Error while attempting to bulk index documents: failure in bulk execution:
[0]: index [logstash-java-beats-rollup], type [_doc], id [Test 2 job$GTvyIZtPhKqi-dtfVd6MXg], message [MapperParsingException[Could not dynamically add mapping for field [#timestamp.date_histogram.time_zone]. Existing mapping for [#timestamp] must be of type object but found [date].]]
[1]: index [logstash-java-beats-rollup], type [_doc], id [Test 2 job$v-r89eEpLvImr0lWIrOb_Q], message [MapperParsingException[Could not dynamically add mapping for field [#timestamp.date_histogram.time_zone]. Existing mapping for [#timestamp] must be of type object but found [date].]]
[2]: index [logstash-java-beats-rollup], type [_doc], id [Test 2 job$quCHwZP1iVU_Bs2fmhgSjQ], message [MapperParsingException[Could not dynamically add mapping for field [#timestamp.date_histogram.time_zone]. Existing mapping for [#timestamp] must be of type object but found [date].]]
...
logstash-java-beats-rollup index is empty, even if there is some stats for the rollup job available.
I'm using elasticsearch v7.2.0
Could you please explain what is wrong with the data, or with the rollup job configuration?